staging: dgap: dgap_fep5: Do not use 0 for NULL pointer

Do not compare NULL pointer with 0.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Lidza Louina <lidza.louina@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgap/dgap_fep5.c

@@ -1245,7 +1245,7 @@ int dgap_param(struct tty_struct *tty)
 		return -ENXIO;
 
         bs = ch->ch_bs;
-	if (bs == 0)
+	if (!bs)
 		return -ENXIO;
 
 	DPR_PARAM(("param start: tdev: %x cflags: %x oflags: %x iflags: %x\n",